1. Field of the Invention
The invention relates to a liquid dielectrophoretic device and a method for controllably transporting a liquid using the liquid dielectrophoretic device.
2. Description of the Related Art
Microfluidic systems or microfluidic chips have been utilized widely in the biotechnological field, the pharmaceutical field, electro optical field, etc., due to their high responsiveness, high sensitivity, high reproducibility, low cost, and low pollution. Microfluidic systems can drive fluids in a mechanical manner or an electrokinetic manner. The electrokinetic manner can be performed through dielectrophoresis or electro-osmosis.
Fan et al. “Reconfigurable liquid pumping in electric-field-defined virtual microchannel by dielectrophoresis”, Lab Chip, pp. 1590-1595, vol. 9, 2009, disclose a conventional liquid dielectrophoretic device (see FIG. 1). The liquid dielectrophoretic device includes upper and lower electrode plates 21 22 that cooperate to define a virtual micro channel 20 for receiving a liquid 100 (the boundary of the liquid 100 in the micro channel 20 is not confined and limited by a real wall but by an electric field in the micro channel 20). The boundary of the liquid 100 in the micro channel 20 is defined by the shape of the lower electrode plate 22. The lower electrode plate 22 has opposite first and second end portions 221, 222. When the liquid 100 is disposed on the first end portion 221 of the lower electrode 22 and when an electric field is formed in the micro channel 20, a dielectrophoretic force is generated to drive flow of the liquid 100 disposed on the first end portion 221 to the second end portion 222. However, the conventional liquid dielectrophoretic device is insufficient to effectively control the flow rate of the liquid.